[转]线上MYSQL同步报错故障处理方法总结(必看篇)

前言

在发生故障切换后,经常遇到的问题就是同步报错,数据库很小的时候,dump完再导入很简单就处理好了,但线上的数据库都150G-200G,如果用单纯的这种方法,成本太高,故经过一段时间的摸索,总结了几种处理方法。

生产环境架构图

目前现网的架构,保存着两份数据,通过异步复制做的高可用集群,两台机器提供对外服务。在发生故障时,切换到slave上,并将其变成master,坏掉的机器反向同步新的master,在处理故障时,遇到最多的就是主从报错。下面是我收录下来的报错信息。

常见错误

最常见的3种情况

这3种情况是在HA切换时,由于是异步复制,且sync_binlog=0,会造成一小部分binlog没接收完导致同步报错。

第一种:在master上删除一条记录,而slave上找不到。

Last_SQL_Error: Could not execute Delete_rows event on table hcy.t1;
Can't find record in 't1',
Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND;
the event's master log mysql-bin.000006, end_log_pos 254

第二种:主键重复。在slave已经有该记录,又在master上插入了同一条记录。

Last_SQL_Error: Could not execute Write_rows event on table hcy.t1;
Duplicate entry '2' for key 'PRIMARY',
Error_code: 1062;
handler error HA_ERR_FOUND_DUPP_KEY; the event's master log mysql-bin.000006, end_log_pos 924

第三种:在master上更新一条记录,而slave上找不到,丢失了数据。

Last_SQL_Error: Could not execute Update_rows event on table hcy.t1;
Can't find record in 't1',
Error_code: 1032;
handler error HA_ERR_KEY_NOT_FOUND; the event's master log mysql-bin.000010, end_log_pos 263

异步半同步区别

异步复制
简单的说就是master把binlog发送过去,不管slave是否接收完,也不管是否执行完,这一动作就结束了.

半同步复制
简单的说就是master把binlog发送过去,slave确认接收完,但不管它是否执行完,给master一个信号我这边收到了,这一动作就结束了。(谷歌写的代码,5.5上正式应用。)

异步的劣势
当master上写操作繁忙时,当前POS点例如是10,而slave上IO_THREAD线程接收过来的是3,此时master宕机,会造成相差7个点未传送到slave上而数据丢失。

特殊的情况

slave的中继日志relay-bin损坏。
Last_SQL_Error: Error initializing relay log position: I/O error reading the header from the binary log
Last_SQL_Error: Error initializing relay log position: Binlog has bad magic number;
It's not a binary log file that can be used by this version of MySQL

这种情况SLAVE在宕机,或者非法关机,例如电源故障、主板烧了等,造成中继日志损坏,同步停掉。

人为失误需谨慎:多台slave存在重复server-id
这种情况同步会一直延时,永远也同步不完,error错误日志里一直出现上面两行信息。解决方法就是把server-id改成不一致即可。

Slave: received end packet from server, apparent master shutdown:
Slave I/O thread: Failed reading log event, reconnecting to retry, log 'mysql-bin.000012' at postion 106

问题处理

删除失败

在master上删除一条记录,而slave上找不到。

Last_SQL_Error: Could not execute Delete_rows event on table hcy.t1;
Can't find record in 't1',
Error_code: 1032; handler error HA_ERR_KEY_NOT_FOUND;
the event's master log mysql-bin.000006, end_log_pos 254

解决方法:

由于master要删除一条记录,而slave上找不到故报错,这种情况主上都将其删除了,那么从机可以直接跳过。可用命令:

stop slave;
set global sql_slave_skip_counter=1;
start slave;

如果这种情况很多,可用我写的一个脚本skip_error_replcation.sh,默认跳过10个错误(只针对这种情况才跳,其他情况输出错误结果,等待处理),这个脚本是参考maakit工具包的mk-slave-restart原理用shell写的,功能上定义了一些自己的东西,不是无论什么错误都一律跳过。)

主键重复

在slave已经有该记录,又在master上插入了同一条记录。

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Last_SQL_Error: Could not execute Write_rows event on table hcy.t1;
Duplicate entry '2' for key 'PRIMARY',
Error_code: 1062;
handler error HA_ERR_FOUND_DUPP_KEY; the event's master log mysql-bin.000006, end_log_pos 924

 

解决方法:

在slave上用desc hcy.t1; 先看下表结构:

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mysql> desc hcy.t1;
+-------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id | int(11) | NO | PRI | 0 | |
| name | char(4) | YES | | NULL | |
+-------+---------+------+-----+---------+-------+

 

删除重复的主键

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mysql> delete from t1 where id=2;
Query OK, 1 row affected (0.00 sec)
 
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
 
mysql> show slave status\G;
……
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
……
mysql> select * from t1 where id=2;

在master上和slave上再分别确认一下。

更新丢失

在master上更新一条记录,而slave上找不到,丢失了数据。

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Last_SQL_Error: Could not execute Update_rows event on table hcy.t1;
Can't find record in 't1',
Error_code: 1032;
handler error HA_ERR_KEY_NOT_FOUND;
the event's master log mysql-bin.000010, end_log_pos 794

 

解决方法:

在master上,用mysqlbinlog 分析下出错的binlog日志在干什么。

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/usr/local/mysql/bin/mysqlbinlog --no-defaults -v -v --base64-output=DECODE-ROWS mysql-bin.000010 | grep -A '10' 794
 
#120302 12:08:36 server id 22 end_log_pos 794 Update_rows: table id 33 flags: STMT_END_F
### UPDATE hcy.t1
### WHERE
### @1=2 /* INT meta=0 nullable=0 is_null=0 */
### @2='bbc' /* STRING(4) meta=65028 nullable=1 is_null=0 */
### SET
### @1=2 /* INT meta=0 nullable=0 is_null=0 */
### @2='BTV' /* STRING(4) meta=65028 nullable=1 is_null=0 */
# at 794
#120302 12:08:36 server id 22 end_log_pos 821 Xid = 60
COMMIT/*!*/;
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;

 

在slave上,查找下更新后的那条记录,应该是不存在的。

mysql> select * from t1 where id=2;
Empty set (0.00 sec)

然后再到master查看

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mysql> select * from t1 where id=2;
+----+------+
| id | name |
+----+------+
| 2 | BTV |
+----+------+
1 row in set (0.00 sec)

 

把丢失的数据在slave上填补,然后跳过报错即可。

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mysql> insert into t1 values (2,'BTV');
Query OK, 1 row affected (0.00 sec)
 
mysql> select * from t1 where id=2;
+----+------+
| id | name |
+----+------+
| 2 | BTV |
+----+------+
1 row in set (0.00 sec)
 
mysql> stop slave ;set global sql_slave_skip_counter=1;start slave;
Query OK, 0 rows affected (0.01 sec)
Query OK, 0 rows affected (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
 
mysql> show slave status\G;
……
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
……

 

中继日志损坏

slave的中继日志relay-bin损坏。

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Last_SQL_Error: Error initializing relay log position: I/O error reading the header from the binary log
Last_SQL_Error: Error initializing relay log position: Binlog has bad magic number;
It's not a binary log file that can be used by this version of MySQL

 

手工修复

解决方法:找到同步的binlog和POS点,然后重新做同步,这样就可以有新的中继日值了。

例子:

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mysql> show slave status\G;
*************************** 1. row ***************************
Master_Log_File: mysql-bin.000010
Read_Master_Log_Pos: 1191
Relay_Log_File: vm02-relay-bin.000005
Relay_Log_Pos: 253
Relay_Master_Log_File: mysql-bin.000010
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1593
Last_Error: Error initializing relay log position: I/O error reading the header from the binary log
Skip_Counter: 1
Exec_Master_Log_Pos: 821

Slave_IO_Running :接收master的binlog信息

Master_Log_File
Read_Master_Log_Pos

Slave_SQL_Running:执行写操作

Relay_Master_Log_File
Exec_Master_Log_Pos

以执行写的binlog和POS点为准。

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Relay_Master_Log_File: mysql-bin.000010
Exec_Master_Log_Pos: 821
mysql> stop slave;
Query OK, 0 rows affected (0.01 sec)
 
mysql> CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000010',MASTER_LOG_POS=821;
Query OK, 0 rows affected (0.01 sec)
 
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
 
 
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.8.22
Master_User: repl
Master_Port: 3306
Connect_Retry: 10
Master_Log_File: mysql-bin.000010
Read_Master_Log_Pos: 1191
Relay_Log_File: vm02-relay-bin.000002
Relay_Log_Pos: 623
Relay_Master_Log_File: mysql-bin.000010
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 1191
Relay_Log_Space: 778
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Ibbackup

 

各种大招都用上了,无奈slave数据丢失过多,ibbackup(需要银子)该你登场了。

Ibbackup热备份工具,是付费的。xtrabackup是免费的,功能上一样。

Ibbackup备份期间不锁表,备份时开启一个事务(相当于做一个快照),然后会记录一个点,之后数据的更改保存在ibbackup_logfile文件里,恢复时把ibbackup_logfile 变化的数据再写入到ibdata里。

Ibbackup 只备份数据( ibdata、.ibd ),表结构.frm不备份。

下面一个演示例子:

备份:ibbackup /bak/etc/my_local.cnf /bak/etc/my_bak.cnf

恢复:ibbackup --apply-log /bak/etc/my_bak.cnf

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[root@vm01 etc]# more my_local.cnf
 
datadir =/usr/local/mysql/data
innodb_data_home_dir = /usr/local/mysql/data
innodb_data_file_path = ibdata1:10M:autoextend
innodb_log_group_home_dir = /usr/local/mysql/data
innodb_buffer_pool_size = 100M
innodb_log_file_size = 5M
innodb_log_files_in_group=2
 
 
[root@vm01 etc]# ibbackup /bak/etc/my_local.cnf /bak/etc/my_bak.cnf
 
InnoDB Hot Backup version 3.0.0; Copyright 2002-2005 Innobase Oy
License A21488 is granted to vm01 ([email protected])
(--apply-log works in any computer regardless of the hostname)
Licensed for use in a computer whose hostname is 'vm01'
Expires 2012-5-1 (year-month-day) at 00:00
See


原文地址:

https://blog.csdn.net/sj349781478/article/details/79492895
 

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